Oldest EmbryoThe sharpest look yet at the oldest known dinosaur embryos (pictured, one of the eggs and its inhabitant) has revealed some "big surprises," a scientist says.
For one thing, the 190-million-year-old babies of Massospondylus—a two-legged dinosaur that preceded the well-known sauropods, such as Diplodocus—do not resemble their parents, according to study co-author Hans-Dieter Sues, a paleontologist at the National Museum of Natural History in Washington, D.C. (See more dinosaur-embryo pictures.)The 8-inch-long (20-centimeter-long) youngster, for example, had long front legs for walking on all fours, and its overall body proportion—such as a short snout—made it "look like a dwarf version of a sauropod dinosaur," the largest animals to walk Earth. (See a sauropod picture.) The babies would have lost these traits as they matured.The discovery suggests Massospondylus had characteristics that "foreshadowed" the later look of the sauropods, he said. (See "New Strong-Handed Dinosaur May Shatter Assumptions.")—Christine Dell'AmoreThe oldest-dinosaur-embryo research appears in the November issue of the Journal of Vertebrate Paleontology.

Photograph courtesy Diane Scott, University of Toronto

Pictures: Oldest Dinosaur Embryos Show "Big Surprises"

The most detailed look yet at the 190-million-year-old babies reveal a lack of teeth, suggesting their parents may have cared for them, a new study says.

November 18, 2010